The last instar and pupa of Pyropyga nigricans (Say, 1823) are described, illustrated, and compared to those of Pyropyga modesta Green, 1961; these species differ in the color pattern of the pronotum and abdominal tergites, and the morphology of the maxilla and labium. Larvae of the genus Pyropyga Motschulsky, 1852 are compared to those of the genera Lamprohiza Motschulsky, 1853, Lucidota LeConte, 1833, and Phosphaenus Laporte, 1833 (all belonging to the tribe Photinini but to different subtribes); on the basis of general body shape and morphology of the head capsule, antennae, and mouthparts, larvae of the genus Pyropyga seem more closely related to those of the genus Lucidota than to those of the other two genera.

Descriptions are presented of larval instars of three species of the colymbetine tribe Matini Zimmermann (Coleoptera: Dytiscidae), Batrachomatus daemeli (Sharp), Matus bicarinatus (Say), and Allomatus nannup Watts, including a chaetotaxic and porotaxic analysis of the cephalic capsule, head appendages, legs, last abdominal segment, and urogomphi. A parsimony analysis based on 32 informative larval characteristics was conducted with the computer program NONA. Members of the Matini are postulated to share a monophyletic origin based on (i) seta TR2 articulated anteroventroproximally on the trochanter; (ii) seta TR5 elongate on the metatrochanter; (iii) seta TA1 elongate and inserted proximally on the tarsus; (iv) antenomere III with a hole-like ventroapical spinula; (v) prementum with the primary setae LA2, LA3, LA4, LA5, and LA8 spine-like and elongate; (vi) presence of secondary setae on the cephalic appendages; and (vii) presence of additional primary setae on the last abdominal segment. A clade Matini + Colymbetini is postulated based on (i) metafemoral seta FE5; (ii) metafemoral seta FE6; (iii) seta TI6 on tibia, all elongate and hair-like; (iv) one-segmented urogomphus; (v) presence of an occipital suture in first instar; (vi) galea elongate; (vii) presence of natatory setae on legs; and (viii) presence of secondary setae on the urogomphus.

The aphid genus Tinocallis Matsumura is revised on a worldwide basis. Notes on its taxonomic position and evolutionary history and a key for the 21 species are presented. Tinocallis ussuriensis Pashtshenko and T. nevskyi lianchengensis Zhang and Qiao are proposed as synonyms of T. takachihoensis, and T. sapporoensis Higuchi is proposed as a synonym of T. nikkoensis Higuchi, T. allozelkowae Zhang and Zhong as a synonym of T. viridis (Takahashi), and T. magnoliae AK Ghosh and Raychaudhuri as a synonym of T. insularis (Takahashi). Tinocallis distinctus MR Ghosh, AK Ghosh and Raychaudhuri is returned to the subgenus Tinocallis s.s. from the subgenus Quednaucallis Chakrabarti. A lectotype designation was made for T. viridis (Takahashi). Tinocallis dalbergicolasp.nov. from Dalbergia hancei Benth. (Fabaceae) in Hong Kong is described and illustrated. It is closely related to T. caryaefoliae (Davis) and T. himalayensis AK Ghosh, MR Ghosh and Raychaudhuri, but has much longer antennae and longer spinal body processes. It also differs from the former species by the smooth mesonotum and from the latter species in having the forewing hyaline and with a complete radial sector.

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), has been the most economically important insect pest of wheat in the northern Great Plains since cultivation began (Weiss and Morrill 1992). The wheat stem sawfly was first reported from wild grasses where populations were often highly parasitized by a number of parasitoids, including Bracon (= Microbracon) cephi (Gahan) (Hymenoptera: Braconidae) (Criddle 1923; Ainslie 1929). A similar species, Bracon lissogaster Muesebeck, was later reported to also attack C. cinctus larvae (Muesebeck 1953; Somsen and Luginbill 1956). These parasitoids are now prevalent in wheat in some regions of Montana (Morrill et al. 1994, 1998; Morrill 1997). The life histories and phenologies of these sympatric idiobiont ectoparasitoids are similar. The ability to distinguish B. cephi from B. lissogaster is essential in elucidating their effects on populations of C. cinctus. We examined 159 females and 123 males of B. cephi from Chouteau, Hill, Stillwater, Teton, and Toole counties in Montana; Burke, Burleigh, Rolette, and Williams counties in North Dakota; Rock County in Minnesota; and southem Alberta (Rockyford and Consort). The 254 females and 215 males of B. lissogaster examined were from Chouteau, Hill, Teton, and Toole counties in Montana. Holotypes were compared to verify identifications.

The effect of delayed mating on the reproductive biology of females of the Oriental fruit moth, Grapholita molesta (Busck), was studied in the laboratory. Expected reproduction, defined as t-th day survival rate × percent successful mating × total viable eggs, was reduced by 13, 36, and 74%, respectively, after a 2-, 5-, and 10-d delay in pairing with a male compared with females that were paired with a male on their day of emergence. Female fertility (percentage of females laying fertile eggs), fecundity (total number of eggs laid), egg fertility (percentage of eggs developing to black head stage), and egg hatch (percentage of eggs hatching) were reduced by delays in mating. The pre-oviposition period of females mated within 24 h of emergence was longer than that of females mated 2, 5, or 10 d after emergence. The duration of the oviposition period declined with delays in mating. Female longevity increased with delays in mating and was greatest in virgin females. The number of eggs laid per day was similar in females paired with a male 2, 5, and 10 d after their emergence. Commencing 2 d after pairing, females paired on their day of emergence exhibited a daily oviposition rate similar to that of females paired 2–10 d after emergence. These observations suggest that the successful control of the Oriental fruit moth using sex-pheromone-mediated orientation disruption (mating disruption) is more likely accomplished by preventing mating than by delaying mating.

To confirm patterns of diversity and differentiation found with isozymes and mitochondrial DNA, we surveyed 10 populations of the white pine weevil, Pissodes strobi (Peck), for randomly amplified polymorphic DNA (RAPD) markers. Four weevil populations were sampled from Sitka spruce, Picea sitchensis (Bong.) Carr (Pinaceae), five from the "interior" spruce of British Columbia [admixtures of white spruce, Picea glauca (Moench) Voss, and Engelmann spruce, Picea engelmanni (Parry)], and one from Jack pine, Pinus banksiana Lamb. (Pinaceae), in Ontario. In each population, 30–60 weevils were assayed with 10 RAPD primers, yielding 74 RAPD markers. Genetic analyses showed that populations from interior spruce and Jack pine formed a distinct complex; as well, Vancouver Island populations formed a distinct group within the Sitka populations. Levels of diversity, both in terms of polymorphic loci and expected heterozygosity, declined from east to west, supporting the contention that P. strobi originated in eastern North America and migrated west, and suggesting that biocontrol methods may be more effective on populations from Sitka spruce, owing to their reduced diversity. These results parallel an earlier isozyme study but, in contrast, the diversity differences and population relationships are demonstrated to be statistically significant, owing to both the much larger number of loci sampled and the attachment of statistical confidence intervals to estimates of diversity and differentiation.

Monitoring of adult flight patterns of the blueberry maggot fly, Rhagoletis mendax Curran, in New Jersey, indicated that the adults are active over a much longer period than previously reported. Captures on Pherocon AM traps over two seasons in wild sites and commercial fields of highbush blueberry, Vaccinium corymbosum L. (Ericaceae), showed that adult flies are present for most of the period from early July to early November. Trap captures in wild sites peaked during July–August, whereas in some commercial fields, peak captures were recorded in September. Emergence patterns were determined by collecting pupae from a wild site and a commercial field at the time of peak fruit infestation. The following year, the wild-site and commercial-field populations showed distinct emergence periods that were in broad agreement with trap captures at these locations. Comparison of an allozyme locus, using individuals collected in commercial blueberry fields, both on Pherocon AM traps and from infested fruit, confirmed that these populations were R. mendax and not any of the sibling species with a similar flight period. These data show that there are considerable phenological differences between some R. mendax populations. Given this plasticity, current debates on evolutionary mechanisms in flies of the genus Rhagoletis Loew should consider that the flight period of R. mendax is probably neither a major limiting factor in the use of hosts with different fruiting schedules nor an effective premating isolation mechanism with respect to other sibling species.

The spotted tentiform leafminer, Phyllonorycter blancardella (F.), overwinters in a photoperiodically induced state of pupal diapause. The critical day length (50% of leafminers enter diapause) for P. blancardella from latitudes of about 42–44°N in southwestern Ontario was 14.25 h at an average August temperature (Environment Canada 1993) of 20°C (Trimble 1994). The development time of actively growing larvae decreased with increased temperature, whereas the development time of diapause-destined larvae was not affected by temperature at the critical day length, suggesting a strong interaction between photoperiod and temperature in the regulation of prediapause development (Trimble 1994). This paper describes the interaction of photoperiod and temperature in the regulation of the rate of egg and larval development of diapausedestined leafminers in the laboratory and in semi-natural conditions.

In field and laboratory tests the wheat midge, Sitodiplosis mosellana (Géhin), oviposited and developed on all 43 accessions of 17 species of diploid, tetraploid, and hexaploid wheats, Triticum L. spp. Ancestral diploid wild wheats had the lowest infestations among species in the genus, and two hexaploid species, Triticum sphaerococcum Percival and Triticum zhukovskyi Men. and Er., were more heavily infested than common wheat, Triticum aestivum L. In five lineages recognized in the genus, infestation increased in association with domestication, although not always in a continuous way. The level of infestation was not related to seed size or the number of seeds in spikes. Wheat species with free-threshing seeds and compact spikes were more infested by larvae than ancestral wheat species with less compact spikes and glumes that were either affixed to or pressed tightly against the seed. An association between glume tightness and spike compactness may explain the positive correlation between susceptibility and spike compactness. Domestication increased the susceptibility of crop wheats to wheat midge, possibly because the free-threshing trait affects the suitability of the glume–seed interface for oviposition and establishment of larvae on the seeds. The ancestral cultivated wheats, Triticum spelta L. and Triticum dicoccoides Körn., are promising sources of resistance to wheat midge because they have the same genomes as modern wheats and relatively low susceptibility. One free-threshing accession of Triticum dicoccum Schrank had relatively low susceptibility to wheat midge and may provide a source of resistance.

We studied the effects of frost on the survival rate of European earwigs, Forficula auricularia L., during the underground phase of their cycle and determined the timing of oviposition, hatching, and death of the adults; we selected couples and inserted them into the ground to a depth of 150 cm in an open area and along the foundations of a heated suburban house in the Montréal area. Oviposition occurred in November and December, and eggs hatched between January and early June, after an average incubation period of 79–189 d depending on experimental conditions. In the open area all adults and eggs at ground surface died, killed by frost, whereas those in the soil along the house foundation did not die. Males died during the fall and early winter; their longevity was shorter than that of females, which survived until shortly after egg hatch. Females and eggs survived temperatures as low as − 3 and − 2 °C, respectively. For successful reproduction, females must keep their developing eggs at a temperature low enough to delay hatching until mid-April.

In Ontario apple [Malus × domestica Mill. (Rosaceae)] orchards, the application of certain pesticides kills phytoseiid predatory mites and causes outbreaks of phytophagous mites. We released a strain of the predatory mite Typhlodromus pyri Scheuten (Acari: Phytoseiidae), obtained from Nova Scotia and with organophosphate- and pyrethroid-resistant traits, into adjacent ’McIntosh’ and ’Red Delicious’ apple orchards and followed its progress over four seasons. The T. pyri strain established in the orchards, became the dominant predator, and was associated with low densities of the phytophagous mites Panonychus ulmi Koch and Tetranychus urticae Koch (Acari: Tetranychidae) and Aculus schlechtendali (Nalepa) (Acari: Eriophyidae). It moved slowly through the orchards and took 4 years to reach the 28th tree (84 m) from the release point in both orchards. The predominant wind direction did not appear to influence T. pyri movement. It was present in high numbers on release trees, or trees near these release trees, each summer after release, unlike other predatory species including Typhlodromus caudiglans (Schuster) (Acari: Phytoseiidae), Amblyseius fallacis (Garman) (Acari: Phytoseiidae), and Zetzellia mali (Ewing) (Acari: Stigmaeidae). This species appears particularly useful for biological control of phytophagous mites in Ontario and is worthy of further testing for conservation and augmentative release.

The bluebeny maggot, Rhagoletis mendax Curran, is a primary insect pest of low bush blueberries, Vaccinium angustifolium Ait. (Ericaceae), in eastern Canada. Eggs are laid in ripening berries and mature larvae emerge from the berries to pupate in the soil. Adult flies can be controlled with insecticides (Wood et al. 1983) and (or) cultural control by bum or flail-mow pruning of bushes. Pruned plants do not bear fruit the season after pruning, and this rotation of fruit and nonfruit years is believed to reduce fly populations by limiting food availability (Lathrop 1952). Adult flies can be monitored by capture on yellow-panel sticky traps or red-sphere traps (Prokopy and Coli 1978; Wood et al. 1983; Neilson et al. 1984). In this study, we focused on the sex ratio of R. mendax flies captured on baited and unbaited yellow-panel sticky traps (Pheroco® AM traps) and on the orientation behavior of flies toward wind-vane traps.

Erannis tiliaria Harr. and Erannis defoliaria Cl. are closely related species (Rindge 1975) that have similar external appearance and flight period. Erannis tiliaria occurs in North America, whereas E. defoliaria is confined to Europe. Erannis defoliaria occasionally damages oak, Quercus spp. L. (Fagaceae), and cheny, Prunus spp. L. (Rosaceae) (Reichart 1993). During its 1975 outbreak, E. tiliaria severely defoliated 200 000 ha of white and yellow birch, Betula alleghaniensis Britt. and Betula papyrifera Marsh. (Betulaceae), respectively (Howse et al. 1995).